GaN-based switching devices, such as hetero-junction field effect transistors (FETs), are well known to be advantageous over other types of conventional FET solutions in that they posses higher power densities, higher breakdown voltages and lower on-resistances. GaN FETs are typically formed as normally ON depletion mode devices. For certain applications, such as power applications, normally ON devices can be less desirable than normally OFF devices because normally ON devices are often operated less efficiently than normally OFF devices and the drive circuitry for normally ON devices has conventionally been more complicated and expensive than normally OFF devices. Thus, it is known to configure a depletion mode GaN FET 10 in a cascoded configuration with a Si FET 12, as shown in FIG. 1A, to make the device operate in a normally OFF enhanced mode. The circuit equivalent enhanced mode GaN FET 14 of FIG. 1A is illustrated in FIG. 1B. However, GaN FETs 10 do not possess an intrinsic body diode, and enhanced mode GaN FETs 14 must rely on the slow and inefficient internal body diodes of the Si FET 12.